FIG. 1 depicts a conventional rifle 10, including an upper receiver 12, a barrel 14, a forend 16 and a front sight 17. As illustrated in FIG. 1, the upper receiver 12 and the forend 16 are aligned in a longitudinal direction, so that accessories mounted on the upper receiver 12, such as a rear sight, can be properly aligned with accessories on the forend, such as forend-mounted target acquisition devices, for example. In conventional rifles, the upper receiver 12 and the forend 16 are aligned during assembly of the rifle 10, using a number of steps, as discussed herein.
As illustrated in FIG. 2, the barrel 14 may be first passed through an opening in the upper receiver 12 and an index pin (not shown) may be retracted into a notch in the upper receiver 12, when the barrel 14 and the upper receiver 12 are in a proper rotational alignment so ammunition can feed from the upper receiver 12 to the barrel 14. The barrel 14 may be then secured to the upper receiver 12 with a barrel nut 18, such as by engaging inner threads (not shown) of the barrel nut 18 with outer threads along the upper receiver 12. After the barrel 14 is secured to the upper receiver 12, the forend 16 may be subsequently secured to the barrel 14 in a manner so that the upper receiver 12 and the forend 16 are aligned. As illustrated in FIG. 2, the forend 16 may include a slot 19 sized to receive the barrel nut 18. A spring-loaded retaining ring 15 may then be provided to secure the forend 16 against the barrel nut 15. The user then checks the alignment between the upper receiver 12 and the forend 16. If they are not properly aligned, the positioning of the barrel nut 18 within the slot 19 is varied, until the upper receiver 12 and forend 16 are aligned. FIG. 3 depicts a cross-sectional view of the interface between the upper receiver 12 and the forend 16 in the conventional rifle 10. A longitudinal gap 13 separates the upper receiver 12 and the forend 16, and the retaining ring 15 may be positioned within the longitudinal gap 13.
Indeed, conventional rifles involve numerous components and steps to assemble the rifle 10 and properly align the upper receiver 12 and the forend 16. Thus, it would be beneficial to provide a more simplified rifle structure, which achieves alignment of the upper receiver and the forend with less effort, in a shorter time frame and with fewer parts.